Doorcheck



Sept. 13, 1932. T. H. BANFIELD DOORGHECK Filed July 21. 1951 '2 Sheets-Sheet 2 WV/57V TUR T. HESANHELD rraa/vax Patented Sept. 13, 1932 UNITED STATES THOMAS H. BANFIELD, F PORTLAND, OREGON DOORCI-IECK Application filed July 21, 1931. Serial No. 552,205.

This invention relates generally to door checks, and particularly to devices for controlling trap doors.

The main object of this invention is to provide a door check which will retard the closing action of trap doors and assist in the opening action, and which will incorporate a means whereby the action of the spring element may be easily and accurately ad usted.

The second object is to construct a door check which will be easy to manufacture and assemble and which will have incorporated therein a locking device for the tensioning means.

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawings, in which:

Fig. 1 is a transverse section trap door.

Fig. 2 is a plan of the device.

Fig. 3 is a view of the locking mechanism in an unlocked position.-

Fig. 4 is a view similar to Fig. 3 but showing the parts in a locked position.

5 is a section taken along the line 55 in Fig. 2.

Fig 6 is an elevation of the device showing the handle and base broken away in section.

Fig. 7 is a section taken along the line 77 in Fig. 6.

Fig. 8 is a section taken in Fig. 5.

Similar numbers of reference refer to similar parts throughout the several views Referring in detail to the drawings, there is shown in section a sidewalk 10 having an opening 11 around the inner and upper edges of which is secured a frame 12 in which is incorporated a channel 13 for drainage purposes.

On opposite sides of the opening 11 are the hinged mountings 14 for the trap doors 15 such as are in common use. The trap doors 15 are usually made of metal of sufficient thickness to withstand the loads which may be imposed thereon. This requires that even the ordinary size of opening must have a door along the line 88 which is employed of considerable weight and it is to facilitate the opening and closing thereof that this dethrough the vice has been constructed, aswell as topic vent the destruction of the doors by the closing of same in a violent manner. Transverse braces 16 are required on the under side of the doors 15 for stiffening purposes.

Turning now to my invention same'will be seen to consist of a round shaft 17 whose ends 18 turn. down and journal in; the bushings 19, one of which is carried' in a standard 20 weldedagainst the frame 21 and the other of which is carried in the standard 22 which is secured to the frame 21 bythe bolts'23.

On the shaft 17 is formed a ratchet wheel 2)4 0? one side of which are formed'the teeth .5 o teeth 26 formed on the hub 27 of an arm 28 whose outer end carries a roller 29 which rides against the under side of the door 15. Pivoted on the side of the arm 28 is a lock 30 which ismounted freely on the bolt 31 and is provided with an extension end'32, by means of which-it is operated. The lock 30 hasa slot 33formed therein on an arc struck from'the center of the bolt 31 andof awidth suflicient to receive the portion 34 of the shaft 17 A washer 35 is placed betweehthe portion 34 of theshaft 17 and the bushing 19.

A torsion spring 36 is mounted'on the shaft 17 and its end 37' passes through the standard 22', while its end 38 occupies a recess in the ratchet 24. p j j On the frame 21- is mounted a latch 39 which in the form of a right angle whose corner 40 can swing into position between the teeth of the ratchet 24 (as shown in Fig. 7). The latch 39 is pivotally mounted on the screw 41 and its projecting end 42 engages a spring 43 which is held by the screws 44 and 45. The

screw 45 also forms a stop for the latch 39 when in an unlocked position (as shown in Fig. 3). The function of the spring 43 is to urge the latch 39 to either a latched or an unlatched position- The operation of-the device is as follows:

When desiring to increase the torsion of the 9 spring 36 it is necessary to move the arm 28 to a jaw clutch adapted to engage similar the position shown infull lines in Fig. 8 in which it will be possible to swing the lock 30 out of engagement with the portion 34 mak ing it possible to slide the arm 28 endwise and Ida? 1 disengage the teeth 25 and 26. If any torsion exists in the spring 36 it will be necessary to move the latch 39 into position before disengaging the teeth 25 and 26.

The arm 28 is now rocked in the proper direction, after which the teeth 25 and 26 are againengaged and additional torsion given the spring 36 by swinging the arm 28. This operation can be repeated or reversed as often as desired until the required spring action is obtained.

While it is necessary to position the latch 39 manually, it is unlatched automatically by a movement of the arm 28.

It can thus be seen that this door check, while being simple to manufacture is easy to assemble and adjust to suit the requirements of the particular installation involved.

Attention is drawn to my United States Patent Number 1,801,840, over which this is an improvement.

I claim: 7

1. A check for trap doors consisting of a pair of standards, a shaft journaling between said standards, said shaft having a ratchet wheel thereon, a rockable arm rotatably mounted on said shaft, a jaw clutch between said rockable arm and shaft, means for preventing the disengagement of said jaw clutch whensaid arm is in a raised position, a torsion spring for urging said ratchet in one direction of travel, and a latch cooperating with said ratchet.

2. A door check having in combination a pair of spaced standards, a shaft journaling in said standards, a ratchet wheel on said shaft, a torsion spring between said ratchet wheel and a standard, a manually set latch which may be brought into engagement with said ratchet teeth to resist an unwinding action of said spring, a door-operating arm mounted on said shaft, a aw clutch between said arm and ratchet, and a lock for said jaw clutch adapted to prevent the disengagement thereof except when said armis in a doorclosing position.

THOMAS H. BANFIELD. 

